A Wearable Electrochemical Gas Sensor for Ammonia Detection

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Monitoring

Background:

• Occupational safety and health management can be enhanced by wearable technology and the Internet of Things for real-time data.
• Existing ammonia (NH3) gas sensors often lack the robustness and flexibility required for continuous wearable applications.

Purpose of the Study:

• To develop a wearable, room-temperature ammonia (NH3) gas sensor utilizing advanced materials.
• To optimize a self-healing hydrogel component for enhanced sensor performance and durability.

Main Methods:

• Fabrication of a wearable gas sensor based on poly(3,4-ethylenedioxythiophene) (PEDOT), electrochemically deposited iridium oxide (IrOx) particles, and a hydrogel film.
• Optimization of hydrogel composition for self-healing, porosity, adhesion, and humidity stability.
• Characterization of chemical structure and morphology using infrared spectroscopy and scanning electron microscopy.
• Evaluation of sensing properties based on a novel potentiometric-like mechanism.

Main Results:

• The optimized hydrogel exhibited desired self-healing, porosity, adhesion, and humidity stability.
• The sensor demonstrated a reversible and selective response to NH3, crucial for accurate detection.
• The flexible, two-terminal sensor achieved a sensitivity of 60 ± 8 μA decade-1 over a wide concentration range (17-7899 ppm).
• The wearable sensor showed stability to mechanical deformations and low power consumption.

Conclusions:

• The developed PEDOT:PSS/IrOx Ps/hydrogel sensor is suitable for wearable applications, offering reliable NH3 detection.
• The sensor's performance, including its wide detection range and robustness, meets occupational safety standards.
• This technology enables real-time monitoring, improving worker safety and environmental health management.